"The venerable Saariputta said this: 'Nibbaana is happiness, Friends, Nibbaana is happiness!' - When this was said, the venerable Udaayi said to the venerable Saariputta: 'But what is happiness, Friend Saariputta, since herein there is nothing felt [n'atthi vedayitan'ti]?' - 'Just this is happiness, Friend, that herein there is nothing felt,' [answered Venerable Saariputta]."

สัพเพ สัตตา สุขีตา โหนตุ

the mountain may be heavy in and of itself, but if you're not trying to carry it it's not heavy to you- Ajaan Suwat

“Felt happiness” (vedayita sukha) means the vedanā that arises dependent on either the five cords of sense pleasure (kāmaguṇa) or the eight attainments (samāpatti). But this happiness is not unqualifiedly happy for it is still subject to saṅkhāara-dukkha. (“Whatsoever is felt, all that is included in dukkha” — MN. iii. 207).

“Non-felt happiness” (avedayita sukha) is not any kind of vedanā, but rather is a term for nirodha. Being free even of saṅkhāra-dukkha this is an unqualifiedly happy state.

Best wishes,Dhammanando Bhikkhu

...and this thought arose in the mind of the Blessed One:“Who lives without reverence lives miserably.”— Uruvela Sutta, A.ii.20

It were endless to dispute upon everything that is disputable.— William Penn Some Fruits of Solitude,